Application of Smear Microscopy, Culture and Polymerase Chain Reaction for Diagnosis of Tuberculous Meningitis in Puducherry
Author(s): Gandhi Kandhakumari, Selvaraj Stephen and Jothimani Pradeep
Tuberculous meningitis, a serious manifestation of extra pulmonary tuberculosis, needs early diagnosis and treatment for better clinical outcome. Conventional methods are time consuming and less sensitive. This study compares the use of Ziehl Neelsen smear microscopy, culture on Lowenstein Jensen medium & Mycobacterium Growth Indicator Tube and polymerase chain reaction. Cerebrospinal fluid collected from 43 patients with clinical suspicion of TBM and five patients with non-infectious meningitis as controls were included in the study. Nested PCR targeting IS6110 gene was carried out for 19 randomized CSF. Analysis of the results was made to assess the role of multiple techniques in the diagnosis of TBM. All CSF including the controls were negative by microscopy and culture. A total of 7 among the 19 CSF tested (36.8%) were positive in TB PCR. PCR plays a crucial role in the diagnosis of TBM where smear and culture remains negative but caution has to be exercised while interpreting the results correlating with clinical features.